Regarding cutting the jack post, It’s hard to say without seeing your setup. Here is a picture of my electric jack post and the weight distribution bars. In my case, if I cut anything off the jack post then something else might become the low point and drag. I think I’d rather have the jack post drag versus other things. I’d probably try an even taller hitch on your tow vehicle until you can figure out a better solution. A properly adjusted weight distribution system can also help.
Moving cargo forward or aft will change the tongue height but it also drastically impacts the sway characteristics while towing. An aft loaded trailer can be very dangerous. Watch this YouTube video as a demonstration:
https://youtu.be/w9Dgxe584Ss?feature=shared
Your trailer specs should have tongue weight guidance. It’s a good idea to weigh your setup to know where to put each item that you typically haul for the correct balance. This may also give you a little more clearance at the jack post.